1. Technical Field
The present invention relates to calibration methods for an image processing device, calibration devices for an image processing device, image processing devices, and display modules.
2. Related Art
There are some techniques that have been proposed to achieve color reproduction that the user desires, using a display panel, such as, a liquid crystal display (hereafter, LCD) panel, an organic electroluminescence (hereafter, EL) panel and the like.
For example, Japanese laid-open patent application HEI 11-261831 (Patent Document 1) describes a technique of performing color space conversion with a three-dimensional lookup table (hereafter, 3DLUT). According to this technique, a one-dimensional lookup table (hereafter, 1DLUT) is prepared for density conversion between output density and output data, and density values from which density fluctuation is eliminated are obtained, by which stationary density fluctuation that may be caused by an image output device and the like is eliminated, and thus the accuracy in forming 3DLUT is improved.
Also, Japanese laid-open patent application 2010-226369 (Patent Document 2) describes a technique for optimizing a color reproduction method in the state that includes gradation conversion when a color conversion matrix and a 1DLUT for correcting the contrast characteristic are combined. According to this technique, color conversion can be accurately and stably performed without depending on individual experience.
However, according to the techniques described in Patent Document 1 and Patent Document 2, there is a problem in that the circuit scale would become enlarged when attempting to realize color reproduction with higher accuracy. In particular, in the case of 3DLUT, the circuit scale becomes substantially larger when the number of grids is increased, such that it is difficult to realize highly accurate color reproduction by a small circuit scale.